Can we put selection pressures onto ourselves?
Is this what discipline is?
Or is Discipline a response to External Selection Pressure?
I mean a good self-induced habit could change you for the rest of your life & it could be passed down to your offspring or others via education.
Or does Selection Pressure only apply to Genetically Heritable Traits?
I guess it brings back the question, do you influence the environment or does the environment influence you? I’m pretty sure it’s both & vice versa but this is an open discussion.
I recommend reading Edward O. Wilsons “The Social Conquest of The Earth.” Wilson was a sociobiologist who focused on ants and wrote copiously about evolution.
I think you are missing here a definition of evolution - I’d recommend checking if your library has an introductory evolution textbook (eg., “How Life Works” by Zimmer & Emlen), I think you would get a lot of value from reading one.
Evolution has to do with changes in the frequency of a trait over time in a population (whether due to selection, random chance, etc). The definition is usually restricted to changes in heritable traits (i.e., traits coded by DNA), so it does not include changes that happen during an organism’s lifespan (eg., snowshoe hares changing from white to brown to white is not an example of evolution). Save for some mutations, your DNA does not change during your life. Since evolution is a process that happens to a population, not an individual (caveat for individuals just being a population of cells), you cannot undergo evolution - instead changes during an organism’s life can be referred to as “plasticity”.
Selective pressure is a separate thing, which is when different individuals leave different numbers of offspring, which is one way that evolution can happen. It is generally not a very nice thing for the organisms themselves, since often it is caused by certain individuals dying or otherwise not being able to thrive as much as others. It is not something that we would want to apply to ourselves - when it is applied purposely to humans it is called eugenics and has led to some horrible events.
Selective pressure doesn’t have to apply to heritable traits - it happens whenever the reproductive success of individuals depends on some variable trait. However, selective pressure will only lead to evolution if that trait is heritable. For example, if you select for leaf shape in a population of plants, but that leaf shape variation is only due to plasticity caused by different amounts of sunlight, the next generation will revert back to the original range of leaf shapes if they are planted in different amounts of sunlight again.
What you are describing here (inheritance of learned traits) is cultural evolution, which is a process similar to biological evolution, in that it follows similar mathematical rules but with some key differences from the way biological evolution works. It is not restricted to humans (eg., evolution of socially-learned elements of birdsong).
Perhaps, I still wonder what makes evolution different from adaptation?
Is evolution just large time-scale adaptation and Adaptation just small-scale evolution?
Ah… that’s the key difference. Thank you for clarifying. Would this mean adaptation is a term used more for the individual?
hmm… what about genome plasticity? Like when hybridization makes the genetics more plastid thus more accepting of foreign species pollen? For example, Inbred/genetically stag-net Vigna heirlooms have a hard time crossing with a different closely related species but a diverse landrace of the same species has an easier time crossing with differnt Vigna species. Or is this refering to a differnt kind of Plasticity?
oh my… so that’s what eugenics is. But it’s not the same thing as selecting which romantic partner you want to have offspring with, altho this technically is also a selection pressure right?
This makes sense, thank you for explaining.
This also includes heritable thru natural hybridization and Mutations + Horizontal Gene Flow?
Ah… this makes so much sense, Cultural evolution is the perfect term for this. Thank you for helping me understand.
Of course Cultural evolution can have impacts on Biological evolution right?
Like how Corn was domesticated, altho now did we domesricate corn or did corn domesticate us? Maybe both cultural evolution & biological evolution push each other?
Food is such a big part of our culture and each subculture/society selects for traits they value. A crop also changes our culture, Italians made Squash into Zuchinni, French turned beans into green beans, meso-americans turned some grass into corn. It’s so fascinating to see what a culture values get expressed in the things we breed them for.
In Utah, Lofthouse’s community loves the long neck butternut squash trait, chefs save him seeds of things that taste good and thus a whole culture gets to be involved in the selection process.
Not quite - they are related but separate processes. There are three terms that need to be distinguished:
Evolution: any change in the frequency of a heritable trait over time in a population (whether that trait be something that affects fitness, or something totally neutral)
Adaptation: a heritable change that increases the fitness of the individuals that have it. This is something that can be selected by natural selection, and it is a process that happens at a population level. Individuals are born with adaptations, they cannot develop them over their lifespan. Note that adaptation can occur through evolution, but not all evolution involves adaptation (sometimes neutral or even harmful traits can increase in frequency due to chance or other reasons, and that is still evolution)
Acclimation: changes that happen during an individual’s lifespan that improve its ability to survive in its environment.
So, when you talk about changes that happen to an individual, that is acclimation, not adaptation. For example, an animal being born with thick fur is an adaptation to cold weather (it is heritable and they were born with it), but an individual being exposed to cold weather and changing their metabolism to become more cold-hardy is acclimation. A confusing part is that the ability to acclimate can be considered an adaptation, but the changes themselves that happen to the individual are acclimation, not adaptation.
Plasticity is something a bit different - it refers to when the genetics of an organism is flexible, in that it can produce more than one possible phenotype with the exact same genetics. For example, if a plant can only produce small leaves, that is not plastic. If however the same individual can produce big leaves or small leaves depending on how much light it receives, then it has plasticity for its leaf shape. When this happens, you might not be able to predict an individual’s genetics from its appearance, because the same genetics can produce different appearances (and the population will not respond to selective pressure because the differences in leaf size are not heritable).
Don’t want to get too much off topic, but no, normally choosing one’s own partner is not eugenics, eugenics is when someone wants to influence other people’s reproductive choices (who can or cannot have kids or who they have them with).
Yes - evolution acts on any genetic variation in a population, no matter how it got there (pre-existing variation from the ancestor of the population, new mutations that arise, genes that make it in through horizontal gene transfer, or genes that enter the population through gene flow or hybrid introgression from the same or different species)
For sure! Evolution always depends on context. A trait that is beneficial in one environment might be neutral or harmful in another, and culturally inherited traits could be considered a part of that environment. (For example: an animal evolving a trait (biological evolution) that makes them better at carrying out a learned behaviour (which they got through cultural evolution). That trait wouldn’t be beneficial if the animal didn’t have that learned behaviour).
This is a point that many Creationists misunderstand. Kent Hovind (rather clumsily) described this exact situation, believing that in so doing, he was debunking evolution. He put a lot of emphasis on “in that particular enviroment,” as if that disproved evolution. A lot of Creationists still think of evolution in the progressive sense implied by the old “Great Chain of Being” concept which envisioned a hierarchy from “inferior” to “superior” creatures.
How long is “over time”? a Year? Decade? Millions of years?
Correct me if I mis understood it, Evolution changes a population over time vs adaptation changes an individual over time?
So it really is just how fast or often adaptation is happening? Does diverse hybrid swarms speed run evolution or adaptation?
For example : I create a hybrid swarm of all 5 domesticated squash species (Cucurbita pepo x C. maxima x C. moschata x C. angyrosperma x C. ficifolia), where all these species are introgressing into each other becoming a homogenized yet still diverse population, eventually becoming a new species (The same way nature has done it throughout Cucurbita evolutionary history). Is this evolution?
Are plant domestication events evolution, adaptation or both?
Ah… so this is the distinction. What would be examples where evolution doesn’t involve adaptation? and adaptation is always a change that makes an organism more fit for their environment, there can never be a mal-adaptation right?
ah… so plasticity it’s how those same genetics get expressed. This would describe plastid phenotype but not platid geneitcs? How would you describe plastid or fluid/moldable genetics (Like in a hybrid swarm/species complex)?
I confused by how they are confused .
Specifically I don’t understand the old “Great Chain of Being” concept, I think that’s why I’m confused about why they are confused.
Evolution is the outcome of selection pressure molding/changing a population. Adaptation is how the population responds to the selection pressure right? So why are they so confused?
The Great Chain of Being is a philosophical and theological concept. Wikipedia explains it clearly: Great chain of being. When you hear someone refer to “higher” or “lower” life forms, this is a legacy of that worldview.
I think you’re on the right track, just a few more things to clear up.
Evolution can happen over any amount of time - technically any time an individual is born or dies, the frequency of traits in their population changes, so that is evolution. Usually meaningful changes take a long time to be noticeable (decades) but some species that live and die quickly might have noticeable evolution on very short time scales (like bacteria and viruses that can evolve shocking changes in days).
To clarify - evolution is changes in the population over time (and if they are good changes, that is adaptation), and acclimation is changes within an individual over its lifetime.
Hybridization can give a population more variation for natural selection to select between. This can make evolution go more quickly compared to needing to wait for those mutations to happen.
Yep, that is evolution! The hybrid swarm will be very variable for a while, and over time the population will lose some of that variation and keep other variation until it becomes stabilized (for example, discarding the flower colour genes from one species and keeping them from another).
Yes, they are evolution (because traits are changing in frequency over time). Adaptations depend on context - a lot of the changes make the plants weaker for growing in the wild, but if they increase the fitness of the plant in a domesticated setting (because people like its traits) then that could be considered an adaptation to living with humans.
Evolution could involve a neutral or even harmful trait. For example, imagine that an acorn is produced with a mutation that does nothing - it is a change in the DNA that does not affect the plant at all. Imagine that acorn just by chance lands in a perfect spot and grows into a very healthy tree that produces dozens of offspring that inherit that mutation. The tree’s success had nothing to do with the mutation, but nevertheless that mutation is now more common. That counts as evolution.
Now imagine that the mutation was actually slightly harmful - it makes the tree produce less pollen. Even though that is bad for the tree, it still by chance landed in a perfect growing spot and managed to produce lots of offspring despite having less pollen. Now that harmful mutation is more common in the population - that is still evolution. Mal-adaptation isn’t really a technical term, it would just refer to the opposite of an adaptation. Adaptation is just a word to use when evolution makes a “good” trait become more common.
Yes - though to clarify, the term for this is “plastic”. “Plastid” is another term, it is a general term to refer to chloroplasts and similar organelles.
You wouldn’t really refer to plastic genetics - if you are talking about a population with a lot of variation because it has a hybrid origin, you would just say something like it is high genetic diversity.
Ah I see, now I understand what it means. It’s crazy humbling from dust we came and to dust we go.
What about whole Genome Duplication events (Where Chromosome Double & generate a whole new Genus, Subtribe, Tribe or even a whole new plant family)?
I feel like it’s possible to create a new subtribe within the Brassiceae Tribe since every genus in that tribe is techically cross-compatible & Chromsome numbers simply double to overcome any hybridization barriers.
YAY! I understood evolution correctly!
I want to garden like this, further evolving all my garden veggies (+ Fruit trees too).
I see, what if adaptability to the local growing enviroment is part of the domestication effort? Kind of like breeding a local eco-type of a crop species to adapt to local rains (Or lack thereof), temperature swings, pests, sun intensity, competition from other plants, ect.
Ah so it really is that simple, like Literally any genetic trait that got changed overtime & is passed onto the next generation is evolution then (Reguardless if it even does nothing at all)?
Thank you for clarifying, what term should we use instead to describe the opposite of adaptation?
So how would you describe highly fluid/moldable genetics? I must be confusing plastid for some other word, it would be the opposite of generically stagnate.
oh my… so that’s what eugenics is. But it’s not the same thing as selecting which romantic partner you want to have offspring with, altho this technically is also a selection pressure right?
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I understood evolution correctly!